flutter Opacity透明度

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
      title: "透明度",
      home: Scaffold(
        appBar: AppBar(
          title: Text('透明度'),
        ),
        body: Center(
            child: Opacity(
          //设置透明度
          opacity: 0.3,
          child: Container(
            width: 100,
            height: 200,
            color: Colors.redAccent,
          ),
        )),
      ),
    );
  }
}